Coated braided hose method and assembly

ABSTRACT

A method of making a lightweight hose assembly including a step of extruding the inner liner. A nonmetallic material is then braided about the exterior of the liner. The inner liner and braided layer are then passed through a reservoir containing a solution of the fluorocarbon polymer. The solvent is then removed, leaving a fluorocarbon polymer coating dispersed throughout the braided layer.

RELATED APPLICATION

This application is a divisional of copending application Ser. No.416,151 filed Oct. 2, 1989, now abandoned, which is acontinuation-in-part of copending application Ser. No. 305,643, filedFeb. 2, 1989, now abandoned.

TECHNICAL FIELD

This invention relates to a hose construction. Specifically, theinvention relates to a hose assembly adapted for carrying vehicle fuels.

BACKGROUND ART

Hose assemblies used to carry fuels are well known in the art. The hoseshould preferably be strong and resistant to heat and chemicaldegradation. These hoses are subject chemical breakdown by the variousfluids which flow through them. Further, these hoses are typicallyrouted through the engine compartment of the vehicle to deliver fuel tothe engines. These engines are hot and thus, the hoses used to carryfuel are subject to breakdown from the heat.

TEFLON hoses provide the necessary physical properties for carryingfuels. A major problem with these types of hoses is that when usedalone, i.e., only a TEFLON liner or conduit, they tend to get bentduring installation and they kink. This kink or deformation remainspermanent and provides constant resistance to fluid flow through thehose. To solve this problem, one known hose assembly includes an innerTEFLON tubular member. The inner tubular member is surrounded by atightly wound metallic braid. The metallic braid allows the TEFLON innertubular member to bend to a certain degree without kinking. However, ifbent past a certain point the metallic braid aids in the kinking of theinner tubular member. This assembly, has three major disadvantages.First, the metallic braid tends to abrade the exterior of the innertubular member. This causes leaks from the inner tubular member. Thesecond problem is that the exterior metallic braided casing is thermallyand electrically conductive. More important is that the metallic braidwill retain heat and transfer the heat to the fuel moving through theinner tubular member causing fuel system problems. Finally, when used inan automotive environment, the metallic braid transmits noise duringoperation of the vehicle which is undesirable.

Copending application U.S. Ser. No. 244,319 filed Sep. 8, 1988 andassigned to the assignee of the subject invention discloses a hoseassembly for carrying fuels. The assembly includes an inner fluorocarbonpolymer liner. In one embodiment, glass fiber is braided about the innerliner. An outer layer of a fluorocarbon foam is disposed over the glassfiber braided layer.

U.S. Pat. No. 4,111,237 to Mutzner et al issued Sep. 5, 1978 discloses ahose assembly. The assembly includes a polychloroprene inner liner. Aglass fiber is then braided about the exterior of the inner liner. Arubber layer is then wrapped over the braided layer. A second braidedlayer of nylon is then placed about the rubber layer. Finally, a coverof polychloroprene is then extruded about the second braided layer.

U.S. Pat. No. 3,547,162 to Schuerer issued Dec. 15, 1970 discloses aplastic pipe assembly. The assembly includes an inner liner of asynthetic plastic made from cross linked olefinic polymers. A fiberbraided layer is disposed over the inner liner. Finally, a foamed layerof synthetic plastic is disposed about the synthetic fiberreinforcement. By utilizing cross linked olefinic polymers, the systemis deficient in that it cannot be used to carry vehicle fuels, as suchfuels would degrade the inner liner. Further, this assembly requires avery thick outer casing to provide the necessary strength.

SUMMARY OF INVENTION AND ADVANTAGES

According to the present invention there is provided a hose assemblycomprising a tubular member and coupling means for connecting the endsof the tubular member to fittings for conducting fluid therethrough. Thetubular member includes an inner organic polymeric liner. A braidedlayer is disposed about the exterior of the inner liner. The assembly ischaracterized by including a coating dispersed throughout the braidedlayer from the outer periphery radially inwardly toward the inner liner.The coating is for strengthening the hose assembly.

A method of making a hose assembly is also provided. The methodcomprises the steps of providing an inner tubular liner of organicpolymeric material. A material is then braided about the exterior of thetubular liner. A solution of organic polymeric material and at least onesolvent is dispersed throughout the braided material.

Accordingly, there is provided a hose assembly and method for making thesame. The assembly includes a coating dispersed throughout a braidedlayer. The coating dispersed throughout the braided layer provides athin coating which covers the fibers in the braided layer. This coatingprovides the necessary strength so that the inner tubular member doesnot kink or deform upon bending. By using a coating dispersed throughoutthe braided material the weight, size, and cost of the hose are allsubstantially reduced. Further, the assembly is resistant to both heatand chemical degradation which makes it suitable for use in automotiveenvironments for carrying fuels. Finally, the assembly is not thermallyconductive. Thus heat from the exterior of the hose will no betransmitted to the fuel through the hose assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

Other advantages of the present invention will be readily appreciated asthe same becomes better understood by reference to the followingdetailed description when considered in connection with the accompanyingdrawings wherein:

FIG. 1 is a perspective view of the preferred embodiment of the instantinvention;

FIG. 2 is a side view partially broken away of the preferred embodimentof the instant invention including a coupling member;

FIG. 3 is a side view partially broken away of the preferred embodimentof the instant invention including an alternative coupling member; and

FIG. 4 is an enlarged sectional view of the hose assembly.

DETAILED DESCRIPTION OF THE DRAWINGS

A hose assembly made in accordance with the instant invention isgenerally shown at 10 in the Figures. The assembly 10 includes a tubularmember, generally indicated at 11, and coupling means, generallyindicated at 20 (as best viewed in FIGS. 2 and 3), for connecting theends of the tubular member 11 to fittings for conducting fluidtherethrough.

The tubular member 11 includes an inner organic polymeric liner 12. Theliner 12 is preferably extruded and has a wall thickness of between0.001 and 0.120 inches. The inner liner 12 is preferably made of afluorocarbon polymer. Specifically, the inner liner is made of thepolymer of tetrafluoroethylene (PTFE), the polymer of fluorinatedethylene propylene (FEP), the polymer of perfluoroalkoxy resin (PFA), orthe polymer of ethelyne-tetrafluoroethylene (ETFE). The fluorocarbonpolymers PTFE, FEP, and PFA are sold under the trademark TEFLON byDupont. The polymer ETFE is sold under the trademark TEFZEL by Dupont.

The inner liner 12 is impervious to fluid flow through the wall. Sincethe inner liner 12 is preferably made of a fluorocarbon polymermaterial, it is resistant to both heat and chemical degradation. Thisallows a variety of fluids, particularly vehicle fuels, to pass throughthe interior of the liner 12 without corroding the liner 12.

The assembly 10 further includes a reinforcing braided or woven layer 13about the exterior of the inner liner 12. The braided or woven layer 13can comprise any nonmetallic material disposed in interleaving fashionor wrapped tightly about the inner liner 12. Preferably the material tobe used for the braided layer 13 is glass fiber. Glass fibers providethe necessary strength. Further, glass fibers are heat resistant whichis important for use in heated environments and for making the assemblyas will be described subsequently.

The braided or woven fibers may be tightly wound or they may be looselywound about the inner liner 12 having wide gaps between adjacent fibers.In the preferred embodiment, the glass fibers are tightly woven suchthat the gaps or spaces between adjacent fibers is minimal. The braidedlayer 13 adds to the strength of the inner liner 12. Particularly, byusing a braided layer 13, the working pressure of the inner liner 12 isincreased, allowing a higher pressure fluid to flow through the innerliner 12. Further, the braided layer 13 adds to the tensile strength ofthe hose assembly 10. When coupling members 20 are disposed on the endsof the tubular member 11, as will be described subsequently, the braidedlayer 13 increases the tensile strength of the hose assembly 10sufficiently to fixedly connect any type of coupling member 20 to thetubular member 11. Finally, the braided layer adds to the hoop strengthof the inner liner.

The assembly 10 further includes an organic polymeric dispersion orcoating 14 in the braided layer 13. Specifically, an organic polymericmaterial is dispersed about the braided layer 13 and is located from theouter periphery of the braided layer 13 radially inwardly toward theinner liner 12 (as best viewed in FIG. 4). The organic polymericmaterial is deposited in the intricies of the braided layer 13. Thecoating 14 preferably comprises a fluorocarbon polymer. Specifically,the coating 14 comprises the polymer of tetrafluoroethylene (PTFE), thepolymer of fluorinated ethylene propylene (FEP), the polymer ofperfluoroalkoxy resin (PFA), or the polymer ofethylene-tetrafluoroethylene (ETFE).

The coating 14 covers or coats the glass fibers of the braided layer 13.That is, the coating 14 covers the fibers of the braided layer 13 fromthe outer periphery radially inwardly. The coating, therefore, does notextend radially outwardly from the outer periphery of the braided layer13. After the material has been coated, each fiber is discernible. Ineffect, what results is a coating 14 having the braided layer 13therein.

The outer coating 14 is preferably formed by first braiding or wrappingthe material 13 about the exterior of the inner liner 12. The organicpolymeric material is then dispersed into the braided material 13 fromthe outer periphery of the braided layer 13 radially inwardly toward theinner liner. Preferably, the organic polymeric material is afluorocarbon polymer in a dispersion. In other words, the coating 14, asapplied, comprises the fluorocarbon polymer and at least one carryingfluid. The preferable fluid is water. It will be appreciated that anysuitable fluid may be used. The fluorocarbon polymer solution coats oris dispersed throughout the entire braided layer 13. Specifically, thefluorocarbon polymer dispersion effectively coats each of the glassfibers from the outer periphery radially inwardly. That is, the glassfibers are coated such that any gap between adjacent fibers will befilled with the polymer dispersion. Also, the outer periphery of eachfiber is completely coated. The carrying fluid is then removed from thedispersion by drying. This leaves a fluorocarbon polymer materialdispersed throughout braided layer 13.

As previously stated, both the inner liner 12 and coating 14 arepreferably fluorocarbon polymers. It is, however, not necessary thatboth the inner liner 12 and coating 14 be of the same fluorocarbonpolymer, although they may be. For example, the inner liner 12 may bemade of PFA while the coating 14 is made of PTFE. Any combination of thefluorocarbon polymers listed may be utilized for the inner liner 12 andcoating 14.

The coating 14 in conjunction with the braided layer 13 allows the innerliner 12 to be bent without kinking. That is, the coating 14 dispersedthroughout the braided layer 13 provides strength to the inner liner 12upon bending. This is commonly referred to as hoop strength. Thus, byusing a polymeric coating 14 dispersed throughout the braided layer, atrim profile assembly is produced which results in the hoop strength ofthe tubular member 11 being increased so that the tubular member 11 canbe bent without kinking the inner liner 12. Further, the outer coating14 adds to the working pressure of the hose. That is, the coating 14provides strength and allows the inner liner 12 to accommodate a fluidunder pressure. Also, the coating 14 hinders abrasion of the tubularmember. Said another way, the coating 14 aids in abrasion resistance ofthe tubular member 11. That is, because the coating is continuous aboutthe outer periphery of the braided layer 13, the braided layer is notsubject to abrasion. The coating 14 resists abrasion.

The assembly 10 further includes coupling means generally indicated at20. The coupling means 20 is for connecting the assembly 10 to a fitting(not shown). The fitting is adapted to cooperate with the coupling means20. Specifically, the coupling means 20 comprises a coupling assembly20. The coupling assembly 20 includes an insert portion, generallyindicated at 22 for inserting into and engaging the interior inner liner12. The insert portion 22 may have a plurality of barbs 24 for engagingthe interior of the inner liner 12 (as best viewed in FIG. 2).Alternatively, the insert portion may have a pair of annular ridges 26,and a smooth portion 28 therebetween (as best viewed in FIG. 3). Thecoupling assembly 20 further includes an engaging portion generallyindicated at 30 extending longitudinally from the insert portion. Theengaging portion is for engaging a fitting (not shown) adapted tocooperate therewith. The engaging portion 30 may comprise a malethreaded member 32 (FIG. 2) or a female threaded member 34 (FIG. 3). Theengaging portion 30 may also comprise any configuration adapted tocooperate with a member to which it will be fixed. For example, theengaging portion 30 may comprise a socket to receive a mating balljoint. Finally, the coupling assembly 20 includes a locking collar 36.The locking collar 36 is disposed about the exterior of the outercoating 14 and is slid over the insert portion 22 of the couplingassembly 20. In this manner, the inner liner 12 is forced into tightfrictional engagement with the insert portion 22 to prevent relativeaxial movement between the inner liner 12 and insert portion 22. Thecoupling assembly 20 can be of any other well known type. For example,the coupling assembly 20 may be of an organic polymeric material and maybe molded about the tubular member 11 for a mechanical connection orfusion bond.

As fluid flows through the inner liner 12, electrical charges tend tobuild throughout the length of the inner liner 12. In order to preventthese electrical charges from accumulating, the inner liner 12 has anintegral longitudinal conductive means coextensive with the length ofthe inner liner 12 for conducting an electrical charge through theliner. Preferably, the inner liner 12 has a conductive strip 16 ofcarbon black. This carbon black is electrically conductive and willdissipate any electrical charges built up by the fluid. Alternatively,the whole inner tubular member 12 can comprise the conductive means.This is done by using carbon black about the entire inner liner 12. Thebraided layer 13 and coating 14 are preferably electricallynon-conductive. This is important in that electrical changes applied tothe exterior of the outer coating 14 will not be conducted throughoutthe length of the tubular member 11 or to the fluid passing through theinterior of the inner liner 12. It will be appreciated that otherconductive material may be used to form the conductive strip 16.

The preferred method for making a hose assembly 10 as shown is asfollows. An inner organic polymeric tubular member 12 is provided.Specifically, the inner tubular member 12 of a fluorocarbon polymer isextruded. A nonmetallic or wound material (preferably glass fiber) isthen braided or wound about the exterior of the inner liner 12 to form abraided layer 13. An organic polymeric material dispersion 14 is thendispersed throughout the braided layer 13 from the outer peripheryradially inwardly toward the inner liner 12. Specifically, the innerliner 12 and braided material are passed through a reservoir containinga dispersion of an organic polymeric material and at least one carryingfluid. Alternatively, the dispersion may be sprayed onto braidedmaterial. Preferably, the dispersion is an aqueous dispersion of afluorocarbon polymer. Because the dispersion is preferably aqueous, thecarrying fluid used is preferably water. The dispersion is disposedthroughout the entire braided layer 13. The carrying fluid, preferablywater, is then removed from the solution. Specifically, the assembly 10is sent to a dryer, a preheat oven which is preferably below the boilingtemperature of the fluid (water). By utilizing an oven below the boilingtemperature of the carrying fluid, a bubbling effect is avoided in thefinal product. The temperature can be above the boiling temperature,however, the assembly (10) may contain many air bubbles in the outercoating 14 if higher temperatures are used. The carrying fluid (water)is removed to leave a coating 14 of an organic polymeric materialdispersed throughout the braided material 13. The assembly 10 is thensintered at a suitable temperature to cure the organic polymeric coating14. Because glass fibers are used for the braided layer 13, the braidedlayer 13 is unaffected by the heat required to sinter the assembly 10.Finally, a coupling member 20 may be secured on one or both ends of thetubular member 11 to secure the assembly 10 to a fitting (not shown) forconducting fluid through the inner liner 12.

The invention has been described in an illustrative manner, and it is tobe understood that the terminology which has been used is intended to bein the nature of words of description rather than of limitation.

Obviously, many modifications and variations of the present inventionare possible in light of the above teachings. It is, therefore, to beunderstood that within the scope of the appended claims whereinreference numerals are merely for convenience and are not to be in anyway limiting, the invention may be practiced otherwise than asspecifically described.

What is claimed is:
 1. A method for constructing a hose assemblycomprising the steps of: providing an inner tubular liner (12) of afluorocarbon polymeric material; applying a braided reinforcing material(13) having gaps extending therethrough about the inner tubular liner(12); dispersing a second fluorocarbon polymeric material (14) and acarrier fluid into the reinforcing material (13), whereby the secondouter fluorocarbon coating covers the braided material but does notextend radially outwardly from the periphery of the braided material,and sintering the assembly.
 2. A method as set forth in claim 1 furthercomprising dispersing the second fluorocarbon polymeric material bypassing the tubular liner (12) having the braided material (13) thereonthrough a reservoir containing the dispersion of the second fluorocarbonpolymeric material.
 3. A method as set forth in claim 1 furthercomprising removing the carrier fluid from the dispersed secondfluorocarbon polymeric material throughout the braided material (13) toleave a single layer of the second fluorocarbon polymeric materialdispersed through the gaps of the braided material.
 4. A method as setforth in claim 3 wherein said sintering of the hose assembly (10) occursafter removing the carrier fluid for curing the outer secondfluorocarbon polymeric material (14) and braided material to the innertubular liner (12).
 5. A method as set forth in claim 4 furthercomprising securing at least one coupling member (20) on the assembly(10) for fastening the assembly (10) to a fitting.
 6. A method as setforth in claim 3 further comprising utilizing a nonmetallic material forthe braided material (13).
 7. A method as set forth in claim 6 furthercomprising utilizing glass fiber for the braided material (13).
 8. Amethod as set forth in claim 1 further comprising forming the innertubular liner (12) by extrusion.
 9. A method as set forth in claim 1further comprising utilizing water as the carrier fluid for providing anaqueous dispersion of the second fluorocarbon polymeric material.
 10. Amethod for constructing a hose assembly comprising the steps of:extruding an inner tubular liner (12) of a fluorocarbon polymericmaterial; braiding a nonmetallic material (13) about the exterior of theinner liner (12); passing the inner tubular liner (12) having thebraided material (13) thereon through a reservoir containing an aqueousdispersion of a second fluorocarbon polymeric material, drying the waterfrom the aqueous solution to leave an outer fluorocarbon material (14)dispersed through the braided material (13), whereby the outerfluorocarbon coating covers the braided material but does not extendradially outwardly from the periphery of the braided material, andsintering the assembly.
 11. A method as set forth in claim 10 furthercomprising securing at least one coupling member to the assembly (10)for fastening the same to a fitting.